The mistakes I see being made is trying to measure Social engagement with the same tools we measure every other digital touch point. In my view email, search, even banner ads, have spoiled marketers into thinking everything can be and must be measured with the metrics used to gauge success in other mediums. I am not sure of what the next stage will be for you, but in the beginning, when you are building your Social Media audience, and testing, I have three stages with which I measure… #1 is Audience growth, #2 is Reactivity… getting them to take an action, and #3 Stickiness… keeping them coming back, engaged and interacting. After you achieve all these I feel measurement will easily follow depending upon what is important to you and your brand.
If you want to continue to reach your market in this social media age, the marketing focus needs to be on building relationships, and metrics need to expand beyond ROI (Return on Investment) to include ROR: Return on Relationship™. If you are not engaging in your field of expertise on Twitter someone else is, so the first issue is that you are missing that opportunity and handing it to others. Second… if you are not talking about your business, your customers and prospects probably are, and you are not there to participate, engage, interact and most important for your business… listen and lead.